1. Field of the Invention
The present invention relates to a power semiconductor module, sealed with resin by transfer molding, which is excellent in terms of productivity. The present invention particularly relates to a power semiconductor module, with a reduced size, which is sealed with resin by transfer molding.
2. Description of the Background Art
One of the resin-sealed power semiconductor modules formed by transfer molding, which is capable of efficiently discharging to the outside the heat generated due to its operation, and capable of large-current operation, is the one in which: power semiconductor elements such as an IGBT and the like are mounted on a circuit pattern joined to a metal heat sink base; and main and control terminals for external connection are joined to the circuit pattern so as to be substantially perpendicular to a surface of the circuit pattern.
A copper block, a cylinder having a screw hole, and a nut fixed by resin molding, are each used for a main terminal connected to a main circuit of this power semiconductor module. The main terminal that is a copper block is joined to external wiring by soldering. The main terminal that is a cylinder having a screw hole, or the main terminal in which a nut is fixed by resin molding, is connected to external wiring by a bolt. Further, a female connector is used as a control terminal that connects to a control circuit of the power semiconductor module, and the female connector is connected to a pin-type terminal provided on an external control substrate.
These main and control terminals are each provided so as to be substantially perpendicular to the circuit pattern surface. Portions of these terminals, which connect to external wiring, are exposed at a surface of the molded resin. Further, wire bonding electrically connects between a power semiconductor element and the main terminal, between a power semiconductor element and the control terminal, and between the power semiconductor elements (see, e.g., Page 7 to 9, FIGS. 2 and 6 of Japanese Laid-Open Patent Publication No. 2007-184315 (hereinafter, referred to as Patent Document 1)).
In the power semiconductor module sealed with transfer molding resin which is described in Patent Document 1 (hereinafter, simply referred to as a power semiconductor module), the wire bonding electrically connects between a power semiconductor element and a circuit pattern on which the main terminals are provided, between a power semiconductor element and a circuit pattern on which the control terminal is provided, and between the power semiconductor elements.
In the power semiconductor module described in Patent Document 1, the wire bonding is used for wiring within the power semiconductor module. For this reason, other than the circuit pattern on which the power semiconductor elements are mounted, the circuit patterns, on which the main and control terminals are mounted, are provided. This causes a problem that size reduction of the power semiconductor module is restricted.
Since a predetermined wide space is necessary for the header of a wire bonding equipment to operate, it is difficult to perform wire bonding in the vicinity of the main or control terminal. In other words, it is necessary to have a wide space between the main or control terminal and a portion on which the wire bonding is performed, in order to allow the wire bonding equipment to operate. This also causes the problem that size reduction of the power semiconductor module is restricted.
The present invention solves the above problem. The object of the present invention is to provide a power semiconductor module, sealed with resin by transfer molding, which can be further reduced in size.